Noncorrosive solution



Patented Aug. 9, 1927.

UNITED- STATES .T ENT' OFFICE.

MORTON ROLAND SHERBINO, OF DETROIT, MICHIGAN, ASSIGNOR TO HYDRAULICBRAKE COMI'ANY, OF DETROIT, MICHIGAN, A CORPORATION OF CALIFORNIA.

NONCORROSIVE soru'rron.

No drawing.

This invention relates to a solution comprising castor oil, alcohol anda phosphorous compound solublev in alcohol, the solution being usedprimarily, although not necessarily, as the fluid medium of a hydraulicbraking system for automobiles.

Heretofore, it has bee-uncommon practice to use a solution. of alcoholand castor oil in substantially equal proportions for actuatingthe'pistons in so-called hydraulic brak ing systems, such for example asshownin the patent to Malcolm Loughead, No. 1,531,- 798 of March 31st,1925. This solution has been used because of the fact that castor oilthus dissolved in alcoholhas no detrimental effect uponrubber used forcup washers and for piping, and at the temperatures encountered inpractice has a sufiiciently con.- stant viscosity for practicalpurposes. It

has been found in practice that even chemically pure castor oil, whenmixed with either ethyl or'methyl alcohol brings about a gradualcorrosion of the commonly used metals, such as iron, steel, brass,copper, and

$5 the metals found in diecasting alloys.

I have found that the corrosion of the above named metals is greatlydecreased by the addition to the castor oil-alcohol solution of acompound of phosphorous, and that these compounds have no detrimentalefi'ect upon the rubber of the hose' or cu washers used in the system. Ihave foun particularly that tri-sodium phosphate (Na PO 12H O)successfully diminishes this corrosion. The quantity of tri-sodiumphosphate used for successfully minimizing the corrosion is aboutone-half gram per gal- .lon of solution, but the amount may be increasedto any amount which can be success- 40 fully dissolved in the alcohol.

One of the forms of corrosion which has given rise to trouble in theoperation of fluid operated vehicle brakes, is the copper sulphide whichforms as a result of the 'presence of sulphur in .the rubber'with whichthe brake solution comes in contact andthe presenceof copper in the tubewhich conducts the brake solution to the work cylinders. This coppersulphide forms along the 5 interior of the copper tubing, creatin a thinscale which, through vibration of t e tubing, becomes dislodged and iscarried by Application filed March 19, 1926. Serial No. 96,084.

the solution into the brake cylinders where it eventually lodges betweenthe rubber cup and the cylinder wall, causing abrasion of the rubber andleakage of the fluid.

, I believe that the compound ofphosphorfor use in a fluid brakingsystem, it is e ually applicable to an use ofa'solution 0 alcohol.

other system ma ing castor or other oil in I claim:

1. A solution of castor oil in alcohol, rendered non-corrosive by theaddition of an alkali metal phosphate.

2. A solution of castor oil in alcohol, rendered inert and non-corrosiveby the additi on of phosphate.

3.-'A solution" of castor oilinalcohol, rena small proportion oftri-sodium dered inert and non-corrosive by the addition of a smallproportion of a sodium phos-' phate. 4. A

tion.

5. A brake solution comprisin alcohol,

an oil soluble in alcohol, and an a ali metal salt containingphosphorous.

' ous acts as a negative catalytic agent, which solution for use influid braking sys I e0 6. The combination with a liquid medium, I

comprising a castor oil and alcohol solution, in contact with metalliccopper and vulcanized rubber, of an alkali metal phosphate held insolution by the medium.

7. A braking sulphur-containing .vulcanized rubber in liquid medium-fob-fluid actuated systems which comprise metal and contact with themedium, the medium com prising a solution of castor oil and alcohol witha small portion of a salt containing phosphorous in solutiontherewithfor minthe corrosion of the metal by the imizing sulphur.

8. In a fluid system exposed both to copper and to sulphur-containingvulcanized rubber,'the combination therewith of a 1i uid mediumincluding alcohol and castor 0i and means for preventing the corrosionof the copper by the sulphur, comprising a small portion of asaltcontaining phosphorous insolution with the alcohol.

9. The process of minimizing the corrosion of copper by the sulphur invulcanized rubher, which consists in covering the area of copper exposedto the sulphur with a liquid medium containing caster-oil, alcohol, and

an alkali metal phosphate.

10. The combinatlon with a solution of castor oil in alcohol and smallamounts of sulphur, of means for minimizing the corrosion of metalliccopper with which the solution comes into contact, comprising a smallportion of a salt containing phosphorous held in the solution.

In witness whereof, I hereunto subscribe my name this 2nd da of March,1926.

MORTON BO AND SHERHINO.

